LONDON (Reuters) - Poorer countries could introduce measures to prevent and treat millions of cases of cancer, heart disease, diabetes and lung disease for a little as $1.20 per person per year, the World Health Organisation (WHO) said on Sunday.

In a study released on eve of the first United Nations high-level meeting on chronic, or non-communicable diseases (NCDs), the WHO said there are many cheap steps governments could take to stem a tide of expensive-to-treat, life-threatening diseases which could bankrupt health systems.

Non-communicable diseases - such as heart attacks and strokes, cancers, diabetes and chronic respiratory disease - account for more than 63 percent of all deaths worldwide, killing 36 million people a year.

The WHO predicts that the global NCD epidemic will accelerate in the next two decades so that by 2030 the number of deaths from these diseases could reach 52 million a year.

NCDs are often thought of as diseases of the wealthy world, where fatty foods, sedentary lifestyles and high consumption of tobacco and alcohol have become part of normal life for many.

But in recent decades such risk factors and illnesses have become far more prevalent in poorer nations, where access to doctors and medicines is limited, and knowledge on and commitment to prevention is patchy.

"Nearly 80 percent of these deaths (from NCDs) occur in low and middle income countries," said Ala Alwan, the WHO's director for NCDs and mental health. "The challenge to these countries is tremendous, but this study proves that there are affordable steps all governments can take to address non-communicable diseases."

The WHO's list of recommendations includes measures that target whole populations, such as excise taxes on tobacco and alcohol, legislating for smoke-free indoor workplaces and public places, as well as campaigns to reduce levels of salt and trans fats in foods, and public awareness programmes about improving diets and increasing physical activity.

Other steps include screening, counselling and drugs for people at risk of heart disease, cervical cancer screening and hepatitis B immunisation to prevent liver cancer.

The two-day UN meeting, starting on Sept. 19 in New York, is the only second-ever such high-level meeting to be held on a threat to global health - the first was a decade ago on HIV/AIDS - and has been billed as a "once in a generation" chance to tackle the predicted wave of NCDs.

In a separate study released on Sunday, the World Economic Forum said the global economic impact of the five leading NCDs - cancer, diabetes, mental illness, heart disease, and respiratory disease - could reach $47 trillion in the next 20 years if nothing is done to prevent them.

Alwan said the WHO's recommendations would "help countries with limited resources work out what the 'best buys' are and what they will cost".

"Implementing them would save literally millions of lives over the next 15 years," he added.